1. Field of the Disclosure
The present disclosure relates generally to image cropping and more particularly to content-driven image cropping methods.
2. Description of the Related Art
Document detection is a common feature in mobile image capture software. This feature facilitates effective document cropping for further image processing of relatively small cropped images. Manipulating cropped documents helps in speeding up image processing as well as promotes more effective use of different image processing techniques. Cropped documents also provide small file sizes that are preferable for document sharing.
Existing document detection and image cropping techniques may detect documents in images captured from mobile devices. These methods detect documents by finding document borders or corners. However, in cases when there is not enough contrast between the captured document and the background, which may occur in mobile-captured images taken in an uncontrolled environment (e.g. non-uniform lighting, variable set-ups, etc.), these techniques may fail to detect document borders and corners. In images that are either of low quality or were taken in an uncontrolled environment with uncontrolled conditions, document borders may become indistinguishable from the background, thereby making document detection difficult or ineffective.
Thus, there is a need for a method of detecting and cropping mobile-captured documents that determines a bounding box for cropping a captured document in an image based on salient features being extracted from document contents. There is a need for a method that does not rely solely on finding highly structured features such as text or straight lines but also on other significant image features that documents in a captured image may have. Furthermore, there is a need for a method that detects captured documents with undistinguished borders.